GPT-6.1 Ultrafast 對決 Xiaomi MiMo v2.6 Pro Ultraspeed：兩條快車道，其中一條會說出代價

The two fastest ways to buy a frontier model went on sale sixteen days apart, and only one of them told you how the speed was produced. GPT-6.1 Ultrafast — the serving tier over GPT-6.1 Sol, which O​penAI released on September 29, 2026 and which gained this tier on October 8, 2026 — is a closed flagship you reach through an API, priced at six times Standard with no published account of what happens between the weights and your request. X​iaomi MiMo v2.6 Pro Ultraspeed, released September 22, 2026, is a speed tier over MiMo-V2.6-Pro, an MIT-licensed checkpoint whose reinforcement-learning environment X​iaomi also published. Both sell latency at a multiple. Only X​iaomi's multiple sits on top of something a customer can inspect, and that difference is worth more to the decision than either speed claim.

這兩條通道的價格是簡單的部分，下面會說明。困難的部分在於，速度等級是關於服務的承諾，而兩家供應商以極為不同的揭露程度做出這項承諾——一家從同系列模型借用其主打數字，另一家則在價目表旁一併附上訓練配方。如果你即將把生產工作負載投入快速通道，揭露程度的落差就是你實際承擔的風險。

價格，兩側位於同一行

這兩種等級皆以標準車道的倍數販售，而兩者的倍數相當接近，因此價格並非區隔它們的因素。

• 標準通道 —— GPT-6.1 Sol 每百萬個符元輸入 $2.00／輸出 $10.00，相較於 MiMo-V2.6-Pro 的 $0.44／$0.87。

• 快速通道 — GPT-6.1 Ultrafast 為 $12.00 / $60.00，對比 MiMo-V2.6-Pro-UltraSpeed 的 $4.35 / $8.70。

• The multiple — exactly 6x on every line for the O​penAI tier, roughly 9.9x on input and exactly 10x on output for X​iaomi's.

• 快取輸入 — GPT-6.1 Sol 在 Standard 上每百萬收費 $0.10，在 Ultrafast 上為 $0.60；我們能查到的 MiMo 價目表並未針對任一通道公布獨立的快取輸入項目。

• 長上下文 — 當輸入超過 272,000 個 token 時，GPT-6.1 Sol 會將整個請求重新計價，輸入與快取費率為 2 倍、輸出費率為 1.5 倍，使 Ultrafast 達到 $24.00 / $1.20 / $30.00 / $90.00。MiMo-V2.6-Pro 具備 1M token 的上下文視窗，且沒有同等公開的價格斷崖。

• 絕對差距 — 兩條快速通道在輸入上相差 2.8 倍，在輸出上相差 6.9 倍，這正是前沿閉源模型與開放權重模型之間的差距，出現在速度層級內，而非標準費率上。

The one-line summary of that block: X​iaomi charges a bigger multiple on a much cheaper model, and O​penAI charges a smaller multiple on a much more expensive one. On output tokens you pay $60.00 per million for the O​penAI lane and $8.70 for X​iaomi's. Neither vendor is offering a discount for speed; both are pricing it as a separate product, which is the first sign that in both cases the standard lane is still the default and the fast lane is an exception you justify per workload.

每個廠商會告訴你關於速度的事

這就是兩個推行方案不再對稱的地方，而這也是頁面上最有用的一點。

O​penAI's published number for Ultrafast is that GPT-6 Astra Ultrafast generates tokens up to 8x faster than GPT-6 Astra in Standard mode in Codex. That is a measurement of a different model, in a different client, phrased as a ceiling. The documentation that covers Ultrafast for GPT-6.1 Sol says the tier reduces the time between generated output tokens and points at a rate card; it does not put a number on the Sol tier at all. So the headline number attached to this rollout is borrowed from the sibling model that has been on Ultrafast since September 29, and no independent party has published a tokens-per-second measurement for either. It may well hold — same serving stack, same mechanism — but it is a vendor ceiling that O​penAI itself did not measure for this model.

X​iaomi's disclosure is different in kind, and the difference is not that it is more precise. Its own material claims UltraSpeed reaches up to 20 times the output speed of the standard Pro service at the same quality. Third-party catalogue listings describing the same model on the same day say roughly 10 times. Both numbers are in circulation, they are not the same number, and nobody has published a measurement that reconciles them. Reading that honestly: "up to 20x" is a vendor ceiling under conditions X​iaomi has not specified, "roughly 10x" is what a catalogue was willing to assert as typical, and the real multiplier sits somewhere in a wide band until someone publishes per-request latency distributions at a stated concurrency level.

So X​iaomi gives you two unreconciled numbers, and O​penAI gives you one number that belongs to a different model. Neither is a fact you can budget against, and the practical consequence is the same for both: measure the tier on your own prompts before you commit a production path to it.

真正重要的不對稱：多出來的位數能換到什麼

撇開速度宣稱不談，這兩條路線分別依附在截然不同的產品類型上，而這正是選擇不再只是價格比較的地方。

MiMo-V2.6-Pro is a sparse mixture-of-experts design that X​iaomi has described in public: 1.02 trillion total parameters with 42 billion activated per token, a 1M-token context window, native multimodality across text, image, video and audio, and an MIT licence tag on the released checkpoints. The release bundle includes a technical report and deployment notes, and X​iaomi says it is open-sourcing the reinforcement-learning training environment and its code so the post-training can be examined and reproduced. The RL run is documented too — 30 steps and roughly 750,000 trajectories per model, under six days, at a combined published spend of about $3,474,715 across the Pro and Flash runs. On DeepSWE v1.1, X​iaomi's own harness with mini-swe-agent at avg@3, the company reports MiMo-V2.6-Flash moving from 48.8 to 65.68 and MiMo-V2.6-Pro from 58.4 to 72.57 across that run. Those are vendor-reported and unreproduced; the distinction between "X​iaomi's harness says 72.57" and "72.57 is the score" is the difference between a claim and a fact.

GPT-6.1 Sol 這些一概不公布。沒有參數量、沒有架構說明、沒有訓練支出數字、沒有檢查點，也沒有授權條款可讀——有的是一份模型卡、一個上下文視窗、2026 年 4 月 30 日的知識截止日，以及一個 API。這是前沿實驗室的常態安排，並非批評。但這對採購決策有個後果，而上市報導往往略過不提：在開放權重這條路線上，令人失望的快速層級是可以補救的。如果 UltraSpeed 最後證明不值得你付出 10 倍的流量成本，同一個檢查點是可以下載的，你可以自行部署，或透過另一家供應商提供服務，這讓你的下行風險以遷移成本為上限。在封閉路線上，令人失望的快速層級就是一筆帳單，以及你得重新調降的速率限制預算；你無法藉由自行執行權重來繞開它，因為根本沒有權重可執行。

One caution about that MIT tag, because it gets flattened in launch coverage. The licence applies to the checkpoints X​iaomi published. UltraSpeed is a hosted service, and hosted services are governed by terms of service rather than by a weight licence. Holding the right to run the checkpoint on your own hardware and holding the right to resell somebody's accelerated serving of it are two different rights, and only the first one comes from the licence file.

複製任一識別碼前，請注意兩個命名陷阱。

本頁標題中的兩個名稱都不是檢查點，而且兩家廠商的說明文件都讓這個錯誤很容易重複發生。

• GPT-6.1 Ultrafast —— 不是一個模型。請求中的識別碼與標準模型相同；等級是由請求中的某個欄位設定，而結果是同一個檢查點以不同的排程方式運行。

• MiMo v2.6 Pro Ultraspeed — 也不是一組獨立的權重。它是 MiMo-V2.6-Pro 檢查點，以更快的路徑提供服務，並作為獨立的計費項目定價。

• 這對基準測試意味著什麼——如果你在相同提示上比較任一模型的兩條通道，預期結果會是相同答案，但速率不同。相同輸入出現分歧內容是要回報的缺陷，而不是你買到的能力。

• What that means for the licence check — for X​iaomi, read the model card. For O​penAI, there is nothing to read, because the weights are not distributed.

There is also a softer asymmetry that shows up in how each tier is sold. GPT-6.1 Sol supports US and EU data residency and global processing, including under Ultrafast, so a workload pinned to European processing has a documented answer. The MiMo rate card we can read does not state residency at all — X​iaomi is selling a model and a serving path, not a compliance posture. For a regulated buyer that single line may decide the comparison before price is considered.

每個通道實際可呼叫的位置

這兩條快速通道都可以透過各自供應商自家的 API 存取，而且兩者都出現在第三方平台上。兩者都不在 OrcaRouter 上，而這一點值得直截了當地說明白，而不是任由比較頁面暗示並非如此。

What is on OrcaRouter is the standard lane of the O​penAI model: openai/gpt-6.1-sol at O​penAI's own list rates of $2.00 per million input tokens and $10.00 per million output tokens, with 0% markup and the provider's price passed straight through, so a vendor repricing lands on our side the same day. Ultrafast is a service-tier flag billed on your own O​penAI account, and no X​iaomi model is hosted here at all. What one key does buy is the standard lane alongside more than 200 other models behind one O​penAI-compatible endpoint, with automatic failover across providers — which is the useful posture when the workload you are protecting is the one that would notice a rate-limit ceiling at three in the morning.

要依序測試哪一條車道

如果你的工作負載是互動式的，而且生成時間是算在真人的時間上，那麼兩個層級都值得試一試，而決定因素不會是價格——而是你那份信任的到期日。開放權重這條路徑讓你驗證完就能離開；封閉這條路徑則要你向唯一能提供服務的供應商驗證，然後留下來。這種不對稱是真實存在的，但它也並非沒有代價：MiMo-V2.6-Pro-UltraSpeed 是託管服務，所以退出是一次遷移，而不是改個設定，而且你遷移過去的那個檢查點，可能與該層級的服務最佳化並不相符。

如果你的工作負載屬於批次或排程類型，那麼 6 倍與 10 倍這兩者都是錯誤的採購；誠實的做法是把它跑在標準通道上，並改把差額花在評估上。

What would change this page: an independent measurement of either tier's output speed at a stated concurrency level, a published residency statement from X​iaomi, or a rate-limit number from O​penAI for the Sol tier that a buyer can plan against instead of requesting. Until those exist, the comparison is a price list against a price list, with one of the two vendors having published considerably more about the object being priced.